An arc flash happens when electric current flows through an air gap between conductors.
The fault current magnetic fields make conductors separate, producing an arc. In other words, arc fault is caused by uncontrolled conduction of electrical current from phase to ground, phase to neutral, and/or phase to phase accompanied by ionization of the surrounding air. Because of the expansive vaporization of conductive metal, a line-to-line or line-to-ground arcing fault can escalate into a three-phase arcing fault in less than a 1/1000 of a second. The heat energy and intense light at the point of the arc is called arc flash.
Accidents caused by touching a test probe to the wrong surface or slipped tool are the most common cause of an arcing fault.
Arc flashes can also be caused by:
Human error
Unfortunately, 80% of accidents are caused by human error – exposed live parts, misplaced tools, earthing fuses, improper installation of parts, wire wrapped around busbars, accidents during testing or fault-finding.
Mechanical faults
Loose parts, parts that break and fail, worn or broken conductor installation, loose wire connections, sparks due to breaks or gaps in the insulation, overheating of connections, busbar splices.
The elements
Dust, corrosion or other impurities on the surface of the conductor, water, oil, grease, water or liquid near electrical equipment, static electricity.
The SIVACON S8 that we manufacture is tested in accordance with IEC 61641 thus restricting the effects of arcing faults.